As the size of integrated circuits decrease, across chip variation (ACV) is becoming an increasing concern. A transistor on one side of an integrated circuit will not always operate similar to a transistor on another side of the integrated circuit. Margins are provided in order to ensure that the integrated circuit operates as desired, which leads to reduced performance and increased power requirements.
It is desired to predict how an integrated circuit will behave, in order to minimize these margins. Performance screen ring oscillators (PSROs) are used to monitor and predict performance in areas of an integrated circuit. However, a PSRO must be in close proximity to the area that is being monitored, and in order to monitor many areas of an integrated circuit, many PSROs are needed. Therefore, current PSROs may take up significant space and wiring.